Datasheet
Identifying Components of Motherboards
25
FIGURE 1.15 An ATX power connector on a motherboard
Today, the headers you will find on most motherboards are for Enhanced IDE (EIDE)—
also known retroactively as Parallel ATA (PATA)—or Serial ATA (SATA). Advanced Tech-
nology Attachment (ATA) is the standard term for what is more commonly referred to as
Integrated Drive Electronics (IDE). The AT component of the name was borrowed from
the IBM PC/AT, which was the standard of the day. However, because ATA is not the only
technology that integrates the drive controller circuitry into the drive assembly (the anti-
quated Enhanced Small Device Interface [ESDI], for example, was another), IDE is some-
what of a misnomer and not the best term when referring only to ATA drives.
Nevertheless, the original ATA standard was referred to as IDE and had an upper limit
of 528MB per logical drive. An enhanced version, EIDE (ATA-2 and higher), was devel-
oped to circumvent the obstacles to accessing more drive space per volume, increasing the
limit to 8GB. Since then, the limit has been increased by the ATA-6 specification to 128PB
(144.12e15). A petabyte (PB) is the number of bytes represented by 2 raised to the 50th power.
If your motherboard has PATA headers, they will normally be black or some other neu-
tral color if they follow the classic ATA 40-wire standard. If your PATA headers are blue,
they represent PATA interfaces that employ the ATA-5 or higher version of the Ultra DMA
(UDMA) technology. These headers require 80-wire ribbon cables that allow increased
transfer rates by reducing crosstalk in the parallel signal. These cables accomplish this by
alternating among the other wires another 40 ground wires. The connectors and headers
are still 40 pins, however. The color coding alerts you to the enhanced performance, which
can be downward compatible with the 40-wire technology but at reduced performance.
86498book.indb 25 7/22/09 5:37:30 AM